1. Field of the Invention
The invention relates to a cylinder cleaning device for cleaning the outer surface of a cylinder in an offset printing press, such as a blanket cylinder, an impression cylinder, a plate cylinder, or an inking cylinder. More particularly, the invention relates to a cylinder cleaning device for use with a cleaning fabric supply roll having a cleaning fabric wound thereon, the cleaning fabric being supplied from the supply roll and pressed against the outer surface of the cylinder to clean the outer surface of the cylinder.
2. Description of Related Art
In a cylinder cleaning device for cleaning the outer surface of a cylinder in an offset printing press, such as a blanket cylinder, there has been generally used a cleaning fabric supply roll having a core about which a cleaning fabric is wound. The device further includes a rigid metal shaft fitted into the core. The shaft is mounted at opposite ends on a frame in the device to support the supply roll for rotation so that the cleaning fabric can be supplied from the supply roll and pressed against the outer surface of the cylinder to clean the outer surface. However, since the shaft is long and heavy, it is troublesome to insert and fit the shaft into the core and then mount the shaft on the frame. Labour and time are required. In addition, a certain device can use only the supply roll having the core which is adapted to fit the shaft of the device, the supply roll and the core being limited in size. Not every supply roll can be used.
There has been also proposed a cylinder cleaning device as disclosed in Japanese Laid-Open Patent Publication No. 234,659 of 1992, in which the the core is directly mounted and held at opposite ends on the frame to support the supply roll for rotation without using the metal shaft. However, in the device, the supply roll has merely a poor rigidness due to lack of the shaft. Accordingly, the center of supply roll may deflect so that the cleaning fabric can not be uniformly supplied. In addition, the core and the supply roll may be disengaged from the frame to fall off. A certain device can use only the supply roll having the core which is adapted to be mounted and held on the frame, the supply roll and the core being limited in size.
In order to overcome the above problems, an attempt has been made to provide a cylinder cleaning device in which the outer surface of the supply roll is engaged with and received by a cross beam to support the supply roll for rotation, the cross beam being mounted on the frame in the device. However, the supply roll can not be stabilized on the cross beam by merely engaging the outer surface of the supply roll with the cross beam. The supply roll may vibratingly move along the cross beam and bounce from the cross beam when the the supply roll is rotated on the cross beam to supply the cleaning fabric. The cleaning fabric can not therefore be uniformly supplied.
By the way, the cleaning fabric may have one surface made of pulp which is intended to be bought into contact with the outer surface of the cylinder for cleaning, and the other surface made of polyester fibers for reinforcing the cleaning fabric. Under these circumferences, it is required to properly set up the supply roll in the device to conveniently supply the cleaning fabric from the supply roll so that not the other surface but the one surface of the cleaning fabric is bought into contact with the outer surface of the cylinder. If an operator conversely positions the opposite ends of the supply roll by mistake when set up, the cleaning fabric will be directed from the supply roll so that the other surface is bought into contact with the outer surface of the cylinder. This has a problem that the polyester fibers adhere to the outer surface of the cylinder to lower the quality of printed product.
It is therefore an object of the invention to provide a new and improved cylinder cleaning device, in which the above problems can be overcome.
Another object of the invention is to provide a cylinder cleaning device in which it is easy to set up the supply roll in the device without labor and time.
Other object of the invention is to provide a cylinder cleaning device in which any supply roll can be used irrespectively of the size of the supply roll and the core.
Other object of the invention is to provide a cylinder cleaning device in which a supply roll can be used even if it has no core.
Other object of the invention is to provide a cylinder cleaning device in which the supply roll is stabilized when rotated so that the cleaning fabric can be uniformly supplied from the supply roll.
Other object of the invention is to provide a cylinder cleaning device which is intended to properly set up the supply roll to conveniently supply the cleaning fabric from the supply roll.
Other object of the invention is to provide a cleaning fabric supply roll for preventing the operator from conversely positioning the opposite ends of the supply roll by mistake when set up.